Stosur knew she would have to play her best to defeat Williams, who on her way to the finals made quick work of both No. 4 seed Victoria Azarenka and No. 1 seed Caroline Wozniacki.

“I've played matches where I feel like I played lights out, can't miss a ball, and it's fantastic,” said Stosur. “But to do it under these circumstances in this kind of final against a player like Serena, for sure I'm going to think it's one of the best days of my career.”

Things got tense early on in the second set, when chair umpire Eva Asderaki awarded a point to Stosur because Williams yelled just before her opponent went to hit the ball. Williams immediately started arguing with Asderaki, and didn't let up the rest of the match.

Afterward, Williams refused to shake the umpire's hand.

Williams outburst could have led to her being barred from participating in next year's Open, but an investigation into the matter led to Williams being issued a $2,000 fine.